clear
clc
x=[0 0.4 0.8 1.2 1.6 2 2.4 2.8];
y=[2 3.5 5 6.3 8 16 35 86];
plot(x,y,'x')
hold on
a=polyfit(x,y,3);
y1=polyval(a,x);
plot(x,y1)
legend({'实际值','拟合值'})
fprintf('y=13.7468*x^3-38.3915*x^2+29.5397*x+0.1455')